MUC2 and infection: To further examine the effect of the interventions involving EcN and EcoR12 EVs on the intestinal function of RV-infected animals, the expression of several genes involved in host immune responses against infection (TLR2, TLR7, IL12, IGA and CD68), mucin production (MUC2) and intestinal maturation (neonatal constant fragment receptor (FcRn)) was measured with reverse transcription–quantitative PCR (RT-qPCR) in the small intestine on days 8 and 16 (Figure 3).